This invention relates to tire changers and, more particularly, to powered tire changers utilizing a pressure fluid for power.
The most pertinent prior art known to the applicant is U.S. Pat. No. 3,255,800, issued June 14, 1966 to Strang et al.
A large number of tire changers embodying the principles disclosed in the above-identified Strang et al patent have been marketed domestically over the years and have been quite successful commercially. Such tire changers utilize an air cylinder for conjointly operating upper and lower bead loosener assemblies as well as a rotatable, tool-receiving center post used in mounting and demounting tires from a wheel. In the last few years, there has been a considerable increase in the number of massive auto servicing centers which, amongst other things, service tires. Not infrequently, such service centers have facilities whereby 15-20 or more automobiles may be simultaneously serviced.
As is well known, many of the tools utilized in servicing automobiles are pneumatically operated and, as a consequence, such centers typically are provided with large air compressor systems to provide a sufficient volume of compressed air at some desired operating pressure to operate the tools employed thereat. In the usual case, the system cannot provide the desired volume of air at the desired pressure when a large number of tools are simultaneously being operated. As a consequence, tire changing operations performed on tire changing stands of the type referred to are slowed due to the reduced air pressure available to the tire changer thereby decreasing efficiency of the operation.
Concurrently, domestic manufacturers of tires, especially high quality belted, radial tires, have been manufacturing their tires with sidewalls having increased stiffness. The placement or removal of such tires on wheels requires additional power over that required in the changing of more conventional tires due to the increased sidewall stiffness and this, in turn, has required even higher pressures at the air supply to ensure that the apparatus can change such tires efficiently.
Moreover, many small tire servicing centers have air supplies providing air at relatively low pressure, which pressure may be sufficiently low as to cause slow operation of the tire changer and, in some cases, preclude the changer from mounting or demounting tires having particularly stiff sidewalls.
In using such apparatus, after a tire has been serviced and replaced on a wheel, or a new tire placed on a wheel, it is necessary that the beads be seated and the tire inflated. Thus, air lines provided with air chucks have been located in proximity to the tire changer and in many commercially available tire changers, the air lines bearing the air chucks have been piped through part of the tire changer.
In either case, long lengths of flexible air hose will be in the vicinity of the tire changer and may impede efficient use of the machine in other of its operations not related to tire inflation.